The present invention relates to a method for mobile data transmission, particularly a method for transmitting multimedia data to a mobile subscriber terminal, as well as to a computer program product and a communication system.
Methods and apparatuses for mobile transmission of various forms or formats of data are known. In this context, the concept of data within the scope of the present invention is also understood to include any kind of information which is made up of individual components. In this case, these individual components or elements may be constructed, organized and/or coded according to different standards. Accordingly, data in this context also may be a multimedia message including various elements from different standards. The concept of mobile transmission is subsequently understood to include transmission which also permits transmission of data from and/or to at least one mobile subscriber.
A mobile radio system based on the Global System for Mobile Communications standard, GSM for short, affords not only voice telephony, for example, but also the opportunity to send and receive information in the form of short text messages of up to 160 characters in length. This service is called the Short Message Service, SMS for short.
For the next generation of mobile radio system, the Universal Mobile Telecommunication System UMTS, a multimedia-compatible variant of a mobile message service is currently being standardized, the “Multimedia Messaging Service” MMS see 3GPP TS 23.140 Version 4.1.0, Release 4; 3rd Generation Partnership Project; Technical Specification Group Terminals; Multimedia Messaging Service (MMS); Functional Description; Stage 2 and 3GPP TS 22.140 v.4.0.1 (July 2000), 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Service Aspects; Stage 1 Multimedia Messaging Service.
Subsequently, information in the form of messages with multimedia contents is simply called multimedia message, MM for short, to provide a better distinction from the text messages of the SMS. In contrast to the SMS, the Multimedia Message Service MMS is not limited to pure text contents. In an MMS, it also will be possible to format texts according to individual taste and to embed any desired contents into a message. These include, by way of example, audio and video contents, still pictures, graphics, texts, inter alia. The revelations disclosed below make general reference to volumes of data which are made up of individual elements of text and/or image data with or without sound and are respectively coded according to the same or different standards, even if a fundamental field of use for the present invention can be seen in applications based on the aforementioned standard.
On the basis of the prior art to date, MMS can be implemented merely using the Wireless Application Protocol WAP. To breach the air interface between an MMS-compatible terminal and the WAP gateway, provision is made for the WAP Wireless Session Protocol WSP to be used, see WAP-209-MMS Encapsulation, Wireless Application Protocol; WAP Multimedia Messaging Service; Message Encapsulation; MMS Approved version, June 2001 and 3GPP TS 23.140 version 4.3.0, Release 4, June 2001; 3rd Generation Partnership Project; Technical Specification Group Terminals; Multimedia Messaging Service (MMS); Functional Description; Stage 2. An MM usually includes a number of parts with a content which is freely definable within broad limits and can be made up of various formats. In this case, an MM basically includes a header part and a data part. The header part or header is made up of defined header fields and contains general information relating to the MM. The data part of an MM may contain one or more elements of different data types and data formats in any order.
For the purpose of transmission, a sender and a desired receiver are connected to one another via a network structure, with the subscriber terminals respectively being connected to a sender-end and a receiver-end network unit via air interfaces. The network units themselves, however, are connected to one another via a landline network, which is organized on the basis of an Internet protocol, for the purpose of data transmission. The change from transmission via an air interface with binary coding to a landline network connection with textual coding necessitates a recoding operation. In this context, particular importance is attached to recoding the header fields. These act as control elements for the data organization within an MM and need to be of e-mail-like design for the purpose of structure alignment with the IP network. Without knowledge of the header fields, an appended data portion no longer can be processed.
As already known from the EDP sector, new data formats are almost constantly appearing whose designation, recognition and/or processing and recoding necessitate continual renewal or updating of the system. Since, in the near future, even more different types of subscriber terminals will, at least in some cases, communicate with one another via mobile radio networks, a large number of very different new codings and identifications can be expected. In the case of a method for mobile data transmission and a corresponding communication system, such continual renewal is becoming almost impossible to carry out, inter alia on account of the large number of network units.
On the basis of the prior art, a binary coding for the header fields is stipulated for the MMS specifically in the specification WAP 209—MMS Encapsulation, Approved version; i.e., explicitly a binary coding for the header field names, header field values and any parameters. The type of coding is based on the coding defined in the “Wireless Session Protocol”, WSP, WAP-203 Wireless Session Protocol, which involves a respective binary code in the form of an 8-bit value or an octet being stipulated for the defined header field names and header field values. These values can be used to code and decode the headers. The binary coding is used between the MMS connection unit under the MMS user application or MMS Client; i.e., it is used on the air interface in a mobile radio system, for example. In addition, mechanisms for textual coding of further header fields are also specified which are compatible with Internet e-mail based on RFC822.
The 3rd Generation Partnership Project 3GPP prescribes the textual coding for the messages in the MIME format in Technical Specification 23.140 v4.3.0, Rel-4: Multimedia Messaging Service; Functional Description; Stage 2 for presenting multimedia messages which are exchanged between MMS connection units or MMS Proxy/Relay stations in the network. This prescription is set out in RFC 2045-RFC 2049 as an extension of RFC822.
Communication between the units is possible without problems only if all the devices involved in transmitting the multimedia message (i.e., all the MMS connection units and MMS user applications involved), implement the same version. If different versions of the specification are implemented, however, the result may be, by way of example, that a unit receives a message with an unknown binary code. If the received message is intended to be converted into the textual form, then problems arise, since the textual coding of the binary code is not known. In such a case, it is not possible to convert the binary code. The receiving unit then merely has the options of ignoring the unknown code or of not performing the transformation and instead responding to the sending unit with an error message. It is not possible to forward the message in textual form including the data part's information represented with binary codes.
The present invention is, therefore, directed toward a method for mobile transmission of multimedia data, a computer program product and a communication system in which it is also possible to process unknown codes without any system-related transmission problems and, in particular, with forward compatibility.